1. Field of the Invention
The present invention concerns an improved combustion chamber intended for fitting to a gas turbine.
2. Description of the Prior Art
A combustion chamber for a gas turbine is known, for example according to U.S. Pat. No. 3,650,106 in which air under pressure coming from a centrifugal compressor is admitted between two concentric chamber cases of sheet metal, toward the closed end of the two cases. A spray nozzle located in the center of the bottom of the chamber injects an atomized liquid fuel into the internal case where it is mixed with some air which penetrates inside this internal case through various perforations whereby combustion gases are turned back so as to circulate in the opposite direction in relation to the air and are driven to a high pressure wheel of the turbine.
A flame is developed along the length of the combustion chamber and it is difficult to situate the turbine with such a combustion chamber under the bonnet of a lorry where space is limited.
A combustion chamber is likewise known in which the flame is first of all directed towards the closed end to be turned around later. This arrangement allows a reduction in the length of the chamber, but in practice the metal components at the end of the chamber eventually melt and break due to, the high temperature there. Because of this, the temperature of the admitted air must not exceed about 200.degree. C. This in turn prohibits the use of heat exchangers which allow recovery of part of the heat of the burned gases by heating the admitted (input) air, to about 580.degree. C., for example. The output of the turbine is therefore limited and the exhaust gases contain unburned fuel which is a source of atmospheric pollution, in addition to the usual nitrogen oxides.